Apparatus having at least two image recording devices and its method for placing at least one component in a desired position on a substrate

ABSTRACT

A method and device are provided for placing components in a desired position on at least one substrate. The device includes a movable arm on which at least two image recording device are provided and separated by a predetermined pitch distance. In addition, two placement devices, which are separated by the same pitch distance, are also present on the arm. The spacing between the image recording devices and the placement devices is one pitch distance or a multiple thereof. A picture may be taken of at least one reference element present on a substrate by at least one image recording device, and simultaneously therewith a component may be placed on a substrate by at least one placement device.

BACKGROUND

The invention relates to a method suitable for placing at least onecomponent in a desired position on at least one substrate by means of adevice. The invention further relates to a device for performing such amethod.

In such a method known from international patent application WO97/38567, an image recording device records an image of a referenceelement of a substrate, whereupon the desired position of the componentwith respect to the location of the reference element on the substrateis calculated from the image. At the same time, the position of thecomponent with respect to a placement device is determined by a secondimage recording device after a component has been picked up from acomponent feeder device by the placement device. Then the placementdevice places the component in the desired position on the substrate.

The method of WO97/38567 has the disadvantage that at any given momenteither only a component is placed by the placement device or only animage is made of a substrate.

A component placement device is also known from WO97/38567; thisplacement device is provided with an arm on which a single placementdevice and a single image recording device are situated, and with atransport belt located below the arm by means of which the substratesare displaced. The component placement device according to the prior artis furthermore provided with a further image recording device.

A disadvantage of the component placement device in WO97/38567 is thatit has a limited capacity, i.e., comparatively few components per unittime can be placed by the component placement device.

An object of the invention is to provide a method by which morecomponents can be placed in a given amount of time. Another object ofthe invention to increase capacity.

SUMMARY

An embodiment of the invention relates to a method suitable for placingat least one component in a desired position on at least one substrateby means of a device. The device is provided with a displaceable arm onwhich at least one placement device and at least one image recordingdevice are present, such that the image recording device records animage of a reference element located on a substrate, whereupon thelocation of the desired position relative to the reference element isdetermined by means of a processor on the basis of the image, andsubsequently the component is placed in the desired position on thesubstrate by the placement device.

The invention further relates to a device that includes, among otherpossible things, at least an image recording device and at least oneplacement device for placing a component on a substrate, the imagerecording device and the placement device being located on an arm.

According to a method according to the invention, an arm is providedwith at least two image recording devices situated at a certain pitchdistance from each other and with at least two placement devicessituated at the same pitch distance from one another, the imagerecording devices and placement devices being distant from one anotherby one pitch distance or a multiple thereof, such that at least oneimage recording device records an image of at least one referenceelement located on a substrate while at the same time at least oneplacement device places a component on a substrate. As an image may betaken while a component is placed, components can be placed successivelyon the substrates more quickly. It is possible to use two imagerecording devices and two placement devices or more than two, with theresult that even more components can be placed per unit time.

According to another embodiment of the method according to theinvention, the image recording devices may take images simultaneously,while at the same time the placement devices may place componentssimultaneously. An advantage of this efficient method is that morecomponents are placed per unit time, i.e., capacity is increased.

According to another embodiment of the method according to theinvention, four substrates may be situated at one and the same pitchdistance from one another, with the image recording devices takingimages of two substrates simultaneously, while at the same time theplacement devices place components simultaneously on the other twosubstrates. In this method, the pitch of the substrate may be equal tothe pitch of the image recording devices and the placement devices. Anadvantage of this embodiment is that the method optimally utilizes thedevice, i.e., comparatively more components per unit time may be placedby means of this method.

According to another embodiment of the method according to theinvention, each image recording device may cooperate with an associatedplacement device, such that first a first image recording device maytake an image while at the same time the associated placement device mayplace a component, whereupon the second image recording device may takean image while at the same time the associated second placement devicemay place a component. This method may be suitable for placingcomponents on substrates that are at a distance from one another greaterthan the pitch distance between the placement devices and imagerecording devices.

According to another embodiment of the method according to theinvention, the placement devices may pick up two componentssimultaneously from a component feeder device. Components may thus bepicked up by the placement devices in an efficient manner.

According to another embodiment of the method according to theinvention, the substrate may be located on a positioning table that iscontrolled by the processor in the plane of the substrate, while thecomponent may be placed in the desired position on the substrate by theplacement device. An advantage of such a method is that components canstill be placed simultaneously on the substrates if there is a slightdeviation between substrates after a displacement of a substrate.

According to another embodiment of the method according to theinvention, the placement devices may be displaceable in the plane of thesubstrate independently of one another. It is possible also in such amethod to correct deviations in orientation between two substrates, sothat two components may be placed in the correct positions on two, notidentically oriented substrates by the placement devices.

According to a device according to the invention, an arm may be providedwith at least two image recording devices situated at a certain pitchdistance from each other and with at least two placement devicessituated at the same pitch distance from one another, the imagerecording devices and placement devices being distant from one anotherby one pitch distance or a multiple thereof. An advantage of such aconfiguration is that the capacity of the device may be comparativelygreat because at least two image recording devices can take a samenumber of images simultaneously per unit time and at the same time atleast two placement devices can place a same number of components perunit time.

According to an embodiment of the device according to the invention, thedevice may further be provided with at least two fluxing devices thathave the same pitch distance as the placement devices. An advantage ofthis is that several components may be fluxed simultaneously. The resultis that the time required for fluxing may be comparatively short,whereby the capacity of the device may further be improved.

According to another embodiment of the device according to theinvention, the device may be provided with at least two further imagerecording devices that have the same pitch distance to one another asthe placement devices. The two further image recording devices may becapable of determining the positions of the components on the placementdevices simultaneously. An advantage of this is that the time requiredfor determining the positions of components on the placement devices maybe comparatively short, so that the capacity of the device according tothe invention may be comparatively great.

According to another embodiment of the device according to theinvention, the image recording devices and the placement devices may besituated in one line, such that the two image recording devices aresituated next to one another and the two placement devices are situatedat one side of the image recording devices. As a result, theconstruction and the control of the device is comparatively simple.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become apparent from the following description, appendedclaims, and the accompanying exemplary embodiments shown in thedrawings, which are briefly described below.

FIG. 1 is a diagrammatic plan view of an embodiment of a deviceaccording to the invention; and

FIG. 2 is a plan view showing an alternative application of the deviceshown in FIG. 1.

DETAILED DESCRIPTION

Corresponding components have been given the same reference numerals inthe Figures.

FIG. 1 shows a device 1 that is provided with an arm 2 that isdisplaceable over a guide 3 by means of a servomotor in and opposite toa direction indicated by arrow P1. The guide 3 is displaceable by meansof two servomotors in and opposite to the directions indicated by arrowsP2 and P3. The directions indicated by the arrows P2 and P3 are parallelto one another and transverse to the direction indicated by the arrowP1. The arm 2 can be accurately aligned as a result of this because theends of the guide 3 can be displaced by two separate servomotors in andopposite to the directions indicated by the arrows P2 and P3. Two imagerecording devices 9, 10 and two placement devices 11, 12 are fastened tothe arm 2. The placement devices 11, 12 have a pitch distance S₁ to oneanother, while the image recording devices 9, 10 have the same mutualpitch distance S₂. The pitch distance S₃ between the placement device 11and the image recording device 10 is equal to the pitch distances S₁,S₂.

A transport device 4 by means of which substrates 5, 6, 7, 8 aredisplaceable in the direction indicated by arrow P4 is situated belowthe arm 2. The substrates 5, 6, 7, 8 have mutual pitch distances S₄which is equal to the pitch S₁, S₂, S₃. The device 1 is further providedwith a component feeder device 13 from which components can be taken bythe placement devices 11, 12. Two fluxing devices 14, 15 and two furtherimage recording devices 16, 17 are situated between the component feederdevice 13 and the transport device 4. The two fluxing devices 14, 15have a pitch distance S₅, and the two further image recording devices16, 17 have a pitch distance S₆. All pitch distances S₁, S₂, S₃, S₄, S₅,and S₆ in FIG. 1 are identical.

The method of the device 1 will be explained in more detail withreference to FIG. 1.

The initial situation is one in which the transport device (alsoreferred to as a “belt”) 4 has moved substrates 5, 6, 7, 8 into thepositions shown in FIG. 1. The positions of reference elements (notshown) present on the substrates 5, 6 have already been determined fromimages recorded by the image recording devices 9, 10.

Subsequently, the arm 2 with the placement devices 11, 12 fastenedthereto is displaced along the guide 3 in or opposite to the directionindicated by the arrow P1, while at the same time the guide 3 isdisplaced in or opposite to the directions indicated by the arrows P2,P3 until the placement devices 11, 12 are situated above the componentfeeder device 13. As the ends of the guide 3 are to a certain extentseparately displaceable in the directions indicated by the arrows P2,P3, it is possible to ensure that the guide 3 will always extendparallel to the transport belt 4.

Components are picked up in the component feeder device 13 by theplacement devices 11, 12. Preferably, the components to be picked uphave a pitch that corresponds to the pitch S₁ between the placementdevices 11, 12, so that the components can be picked up simultaneously,for example by means of pipettes (not shown) present in the placementdevices 11, 12. Then the placement devices 11, 12 may be displaced bythe arm to a position situated above the two further image recordingdevices 16, 17, where the two further image recording devices 16, 17simultaneously determine the positions of the picked-up components withrespect to the placement devices 11, 12.

The placement devices 11, 12 are subsequently moved by the arm 2 topositions situated above the fluxing devices 14, 15, where flux isapplied to the components. Subsequently, the devices 11, 12 are moved toabove a desired position on the substrates 5, 6. The desired positionsare determined from the locations of the reference elements on thesubstrates 5, 6 determined previously by the image recording devices 9,10 and from information relating to the desired positions of thecomponents to be placed with respect to the reference elements.

The moment the placement devices 11, 12 are each above the respectivedesired position on the substrate 5, 6, the image recording devices 9,10 are located above respective portions of the substrates 7, 8 on whichcomponents are to be placed in a later phase similar to the componentsbeing provided at that moment on the substrates 5, 6.

While the components are being placed on the substrates 5, 6 by theplacement devices 11, 12, images can be, and are indeed simultaneouslytaken of the substrates 7, 8 by the two image recording devices 9, 10.The substrates 5, 6, 7, 8 may be displaced over a distance equal totwice the pitch S₁ by the transport belt 4 after the components havebeen placed and the images have been taken. As a result, the substrates7, 8 will come to lie below the placement devices 11, 12, and at thesame time new substrates (not shown) may be positioned below the imagerecording devices 9, 10. The placement devices 11, 12 may be moved to aposition above the component feeder device 13 again during thedisplacement of the substrates.

FIG. 2 shows an alternative application of the device according to theinvention. Substrates 20, 21 have been displaced to a position below theimage recording devices 9, 10 and placement devices 11, 12 in the device1 by means of the transport belt 4, which substrates 20, 21 have alength greater than the pitch distance S₁, S₂, S₃. In such a case, thesubstrates on the transport belt 4 are given a pitch that is equal to amultiple of the pitch S₁, S₂, S₃. In the situation shown in FIG. 2, thepitch S₇ of the substrates 20, 21 is equal to 2S₁. The operation of thedevice 1 in such a situation is as follows.

Components are taken from the component feeder device 13 by theplacement devices 11, 12 in the manner previously described. As the twocomponents will be placed on the same substrate, the components may beidentical or different. Subsequently, the further image recordingdevices 16, 17 determine the locations of the components with respect tothe placement devices 11, 12 in the manner previously described, and thecomponents are provided with flux by the fluxing devices 14, 15. Thenthe placement device 12 is moved into a desired position above thesubstrate 20. As the distance between the image recording device 10 andthe placement device 12 is equal to 2S₁, which distance is equal to thepitch S₇ of the substrates 20, 21, the image recording device 10 will bepositioned above a position of the substrate 21 on which in a subsequentphase a component is to be placed identical to the one currently beingplaced on the substrate 20 by the placement device 12. An image can be,and is indeed taken of the substrate 21 by the image recording device 10while the component is being placed on the substrate 20.

The placement device 11 is subsequently moved into a desired positionabove the substrate 20. The image recording device 9 will now be abovethat portion of the substrate 21 where in a later phase a component isto be placed identical to the one currently being placed on thesubstrate 20 by the placement device 11.

Accordingly, an image can be, and is indeed taken of the substrate 21 bythe image recording device 9 while the component is being placed on thesubstrate 20. After the desired number of components has been placed onthe substrate 20, the substrates 20, 21 may be moved by the transportbelt 4 in the direction indicated by the arrow P4 over a distance S₇,such that the substrate 21 is positioned below the placement devices 11,12, and a new substrate (not shown) may be positioned below the imagerecording devices 9, 10, whereupon the entire cycle can be repeated.

If two components having the same mutual pitch as the placement devices11, 12 are to be placed on a substrate 20, 21, it is possible to placethese components simultaneously on the substrate. In such a situation,the image recording devices 9, 10 will take images simultaneously of anadjoining substrate.

It is also possible to place different components on a single substratebefore the substrate is displaced in the direction indicated by thearrow P4 by the transport belt 4. If several components are placed on asingle substrate, several images of the substrate may first be taken ina prior phase so as to determine the desired position for each componentto be placed.

Given the disclosure of the present invention, one versed in the artwould appreciate that there may be other embodiments and modificationswithin the scope and spirit of the invention. Accordingly, allmodifications attainable by one versed in the art from the presentdisclosure within the scope and spirit of the present invention are tobe included as further embodiments of the present invention. The scopeof the present invention is to be defined as set forth in the followingclaims.

1. A method suitable for placing at least one component in a desiredposition on at least one substrate by means of a device, wherein thedevice comprises a displaceable arm on which at least two placementdevices and at least two image recording devices are provided, whereinthe at least two image recording devices are separated from each otherby a certain pitch distance, wherein the at least two placement devicesare separated from each other by substantially the same pitch distance,wherein said image recording devices and placement devices are separatedfrom each other by one said pitch distance or a multiple thereof, themethod comprising the steps of: recording, using at least one of theimage recording devices, an image of at least one reference elementlocated on a substrate; determining, by processing said image, thelocation of the desired position relative to the reference element;placing, using at least one of the placement devices, the component inthe desired position on the substrate while the at least one imagerecording device records the image of at least one reference elementlocated on a substrate.
 2. The method according to claim 1, wherein thestep of recording comprises: recording, using at least two imagerecording devices, the image of the at least one reference elementlocated on the substrate while placing, using the placement device,components on the substrate.
 3. The method according to claim 2, whereinfour substrates are separated from each other by substantially the samepitch distance, and wherein the method comprises the steps of: imagingtwo of the four substrates with the image recording devices whileplacing two components on the other two substrates using the placementdevices.
 4. The method according to claim 1, wherein each imagerecording device cooperates with an associated placement device, andwherein the method comprises the steps of: imaging, using a first imagerecording device, at least one reference element located on a firstsubstrate while the associated placement device places a component onthe first substrate; and thereafter imaging, using a second imagerecording device, at least one reference element located on a secondsubstrate while at the same time the associated second placement deviceplaces a component on the second substrate.
 5. The method according toclaim 1, wherein the method comprises: picking-up, using the placementdevices, two components simultaneously from a component feeder device.6. The method according to claim 1, wherein the substrate is located ona positioning table, and wherein the method comprises: controlling thepositioning table in the plane of the substrate.
 7. The method accordingto claim 1, wherein the placement devices are independently displaceablein a plane of the substrate.
 8. A device comprising: an arm; at leasttwo image recording devices positioned on the arm, wherein the imagerecording devices are separated from each other by a pitch distance; andat least two placement devices positioned on the arm, wherein theplacement devices are configured to place a component on a substrate,and wherein the placement devices are separated from each other by thesame pitch distance, wherein the image recording devices and theplacement devices are separated from one another by one pitch distanceor a multiple thereof.
 9. The device according to claim 8, furthercomprising: at least two fluxing devices that are separated bysubstantially the same pitch distance as the placement devices.
 10. Thedevice according to claim 8, further comprising: at least two additionalimage recording devices that are separated by substantially the samepitch distance as the placement devices.
 11. The device according to anyclaim 8, wherein the image recording devices and the placement devicesare substantially situated in a line.
 12. The device according to claim11, wherein the two image recording devices are positioned next to oneanother in the line, and wherein the two placement devices arepositioned to one side of the image recording devices in the line. 13.The device according to claim 8, wherein one of the placement devices islocated on the arm between two image recording devices.